Neurotrophic factor S100 beta in major depression.

Disturbances in the serotonergic system are considered to be implicated in the pathophysiology of depressive disorders. The possible role of the neurotrophic factor S100 beta, which is suspected to regulate regeneration of serotonergic synapses, has not been investigated in depressive disorders. The S100 beta concentration in the cerebrospinal fluid was measured in 11 patients with the current diagnosis of mild or moderate depressive episodes (DSM-IV) and in 11 matched control patients. Using the t test for paired samples, the presence of a depressive episode was significantly associated with an elevation of the cerebrospinal fluid concentration of S100 beta (t = 2.6, d.f. = 10, p = 0.024). Replications of this finding in severely depressed patients are necessary to confirm the association between neurotrophic factor S100 beta and depressive disorders.